Various electronic apparatuses, such as portable telephones and personal computers, have a small size and high performance, and accordingly, a switch device used in such apparatuses is required to be small, thin, and operate reliably.
FIG. 5 is a perspective view of a conventional switch device 501. Slide switch 1 includes case 502 made of insulating resin, lever 3 made of insulating resin, and cover 4 made of thin metal plate. Case 502 has a substantially box shape having an opening in an upper surface of the case. Lever 3 protrudes towards a front from case 502. Cover 4 covers the upper surface of case 502.
Switch contacts, such as a fixed contact and a movable contact, are accommodated in case 502. Upon lever 3 sliding in left and right directions, these switch contacts are electrically connected and disconnected. Plural terminals 5 connected to switch contacts protrude from both sides of a lower surface of case 502.
Plural wiring patterns are formed on upper and lower surfaces of wiring board 6. Plural lands 7 are provided on the upper surface of wiring board 6. Terminal 5 of slide switch 1 is connected to land 7 by, e.g. soldering. Slide switch 1 is mounted to an anterior edge of wiring board 6 while lever 3 protrudes towards the front, thus providing the switch device 501.
Switch device 501 is mounted behind an operating panel of an electronic apparatus while lever 3 protrudes from the operating panel. Terminal 5 of slide switch 1 is connected electrically to an electronic circuit of the electronic apparatus via the wiring pattern on wiring board 6, a connector, or a lead wire connected to the wiring pattern.
Lever 3 protruding from the operating panel is slid in the left or right direction, the switch contacts in case 502 are electrically connected and disconnected. An electrical signal due to the electrical connection and disconnection of the switch contacts is supplied from terminal 5 to the electronic circuit of the electronic apparatus via, e.g. the wiring pattern, thereby switching between various functions of the electronic apparatus.
Lever 3 of slide switch 1 is activated with a force of about 1N to 3N as well as a push button of another switch, such as a push switch including a movable contact having a dome shape. Upon being activated, the displacement of lever 3 is large and ranges from about 2 mm to 3 mm, while the displacement of the push switch ranges from about 0.2 mm to 0.5 mm.
When a large force is applied to lever 3 while being activated, the force applied to case 502 may cause terminal 5 to be peeled from land 7, thus making electrical connection between terminal 5 and land 7 unstable or causing switch 1 to be displaced thereby preventing switch 1 from operating reliably.
A case 502 may accommodate therein a spring for restoring lever 3 to its original position by its elastic restoring force when a hand is released after manipulating lever 3. In the case that slide switch 1 is such an auto-return type slide switch, the spring may produce a shock causing the above problem.
In switch device 501 including slide switch 1, claws provided on a chassis of the electronic apparatus contact right and left sides of switch 1 in order to avoid such problem, hence causing the structure of switch device 501 to be complicated.